There is a merit system board of the Commission. The board consists of three members appointed by the Commission. Nothing contained in this subtitle requires that an appointment be made for the purpose of rotating majority membership on the board between residents of Montgomery County and Prince George’s County. The Commission may reappoint a member of the board. Each member of the board: shall be a resident of the regional district; shall be knowledgeable and experienced in personnel matters; and may not be a member or employee of the Commission or the executive director, secretary–treasurer, or general counsel appointed by the Commission under § 15–109 of this article. Not more than two members of the board may reside in the same county. Each member of the board shall be appointed for a term of 4 years and continue to serve until the member’s successor is appointed. The Commission shall fill each vacancy on the board in the same manner as an original appointment. The Commission shall designate one member of the board to serve as the chair at the pleasure of the Commission.